The Mathematical Practitioners 



The Rittenhouse Brothers 



N' 



■OTABLE AMONG THE AmeHcan practitioners was David Ritten- 

 house (1732-1796) of Norristown and Philadelphia, Pennsylva- 

 nia, who was established as a clockmaker and surveyor in Philadelphia 

 by 1749. He surveyed the boundary between Pennsylvania and 

 Delaware in 1763 with instruments of his own design and con- 

 struction. Six years later, in 1769, he successfully calculated the 

 transit of Venus and later observed that planet with astronomical 

 instruments he had constructed himself. In the following year, 

 1770, he built the first American astronomical observatory, in 

 Philadelphia. Two orreries that he designed and built — at the 

 University of Pennsylvania and at Princeton University — survive 

 as outstanding examples of American craftsmanship.^ Several of 

 his surveying and astronomical instruments are exhibited in the 

 collections of the U.S. National Museum. David Rittenhouse 

 is credited with being the originator of a declination arc on the 

 surveying compass, a feature to be copied by a number of later 

 instrument makers. 



David's brother, Benjamin Rittenhouse (1740-C.1820), served 

 in the Revolution and was wounded at Brandywine. He super- 

 intended the Government's gunlock factory at Philadelphia in 

 1778 and achieved recognition as a maker of clocks and surveying 

 instruments (see fig. 8).^ During one period of his career he worked 

 in partnership with his brother David. An interesting advertise- 

 ment appeared in the May 14, 1785, issue of The Pennsylvania 

 Packet: 



WANTED, An ingenious Lad not exceeding 14 years of age, of a reputable 

 family, as an Apprentice to learn the Art and Mistery of making Clocks and 

 Surveying Instruments. Any lad inclining to go an apprentice to the above 

 Trade, the terms on which he will be taken may [be] known by enquiring of 

 Mr. David Rittenhouse, in Philadelphia, or at the subscriber's house in 

 Worcester township, Montgomery county. Benjamin Rittenhouse. 



^ HiNDLE, op. cit. (footnote 6). 



^ George H. Eckhardt, Pennsylvania Clocks and Clockmakers (New York: 

 Devin-Adair Co., 1955), p. 190. 



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